This extreme fire behavior likelihood dataset represents the probability of heading flame lengths exceeding 11 feet, which is generally considered a threshold for extreme fire behavior during fire operations. Probability is calculated using heading-only fire behavior and is weighted according to weather type probabilities (WTP), incorporating both temporal frequencies and the influence of high-spread conditions. This raster could be used for pre-planning fire suppression operations for a given area of the landscape. This layer, based primarily on landscape conditions at the beginning of the 2020 fire season, was aggregated from the original 30m to 90m resolution by mean.

Wildfire Exposure Simulation Tool (WildEST) is a scripted geospatial process used for simulating potential fire behavior characteristics that addresses two shortcomings of current methods. WildEST performs multiple deterministic simulations under a range of weather types (wind speed, wind direction, fuel moisture content). Rather than weighting results solely according to the temporal relative frequencies of the weather scenarios, the WildEST process integrates results by weighting them according to their weather type probabilities (WTP), which appropriately weights high-spread conditions into the calculations. Most WildEST results apply to the head of the fire. For fire-effects calculations, WildEST also generates flame-length probability rasters that incorporate non-heading spread directions, for which fire intensity is considerably lower than at the head of the fire. These “NVC” FLPs are analogous to FLP rasters produced by FSim. WildEST was run for the CAL fuelscape at 30-m resolution using gridded historical California weather data provided by CALFIRE.